I start by placing the cocoa powder, cinnamon, nutmeg, brown sugar, and vanilla in the saucepan. Then I add a small splash of milk and whisk until it forms a smooth paste without lumps.
Once the paste is smooth, I pour in the remaining milk and keep stirring over medium heat. I watch carefully so it doesn’t boil over or scald. Continue whisking until it’s hot, but not at a full rolling boil.
I remove from the heat and immediately pour into mugs. On top, I add whipped cream if using, and sprinkle the dark chocolate shavings for that finishing flourish.